Exploration of Time Reversal for Wireless Communications within Computing Packages

TL;DR

This paper investigates the application of time reversal techniques to wireless intra-chip communication channels, demonstrating significant improvements in signal quality and BER performance by exploiting the static, multipath-rich environment within a chip.

Contribution

It introduces the use of time reversal for in-package wireless channels, showing its effectiveness in reducing ISI and enhancing communication reliability on chips.

Findings

TR achieves spatiotemporal focusing in chip channels

TR-based transmissions outperform non-TR in BER by an order of magnitude

The technique is effective across different transmission rates and power levels

Abstract

Wireless Network-on-Chip (WNoC) is a promising paradigm to overcome the versatility and scalability issues of conventional on-chip networks for current processor chips. However, the chip environment suffers from delay spread which leads to intense Inter-Symbol Interference (ISI). This degrades the signal when transmitting and makes it difficult to achieve the desired Bit Error Rate (BER) in this constraint-driven scenario. Time reversal (TR) is a technique that uses the multipath richness of the channel to overcome the undesired effects of the delay spread. As the flip-chip channel is static and can be characterized beforehand, in this paper we propose to apply TR to the wireless in-package channel. We evaluate the effects of this technique in time and space from an electromagnetic point of view. Furthermore, we study the effectiveness of TR in modulated data communications in terms of BER as a function of transmission rate and power. Our results show not only the spatiotemporal focusing effect of TR in a chip that could lead to multiple spatial channels, but also that transmissions using TR outperform, BER-wise, non-TR transmissions it by an order of magnitude